Weedy Rice Challenges Some Rice Growers

Weedy Rice Challenges Some Rice Growers

September 2, 2016

Weedy Rice Crops Ups Again in Northern Calif. Rice Fields

By Patrick Cavanaugh, Farm News Director

In Northern California, rice growers typically prepare to start harvesting in mid-September, but some growers have endured a lot of weed pressure from weedy rice (Oryza), also known as red rice, according to Whitney Brim-DeForest, a UC Cooperative Extension Rice Farm Advisor in Sutter, Yuba, Placer, and Sacramento Counties who focuses particularly on weeds. Red rice is actually the same species as cultivated rice, but it produces far fewer grains per plant and is therefore considered a pest.

Brim-DeForest said weedy rice is common in the Southeast, but not in California. “We've been pretty lucky in California in that we actually don't have a big problem with it,” she said. “It's a big problem down in the southern U.S. and they have been dealing with it in for a long time; but we have had it crop up. I think the last time was in 2006, and we managed to deal with it. It somehow popped up again in the last couple of years, so we're dealing with it again."

How weedy rice reached California is apparently a mystery. “We don't really know the source of it, to be honest," said Brim-DeForest. "We're investigating that through research, hopefully starting this fall,” she said.

Brim-DeForest said growers have few choices to control weedy rice. “Growers that have it will either have to rogue¹ it out, pull it out by hand or sacrifice that field and spray it with Roundup,” she said, “which would kill the rice as well. And, if the rice grower doesn't know he has weedy rice in the field, it could hurt him later at the rice mill,” explained Brim-DeForest.

“Once harvested, the rice goes to the mill. If a certain amount of red rice bran (the outer layer surrounding the rice grain) is discovered, the mill will not accept it and could reject the entire load," she said.